A conventional laser machining apparatus is provided with a laser emission device, a scanner that scans the laser beam emitted from the laser emission device, and a controller that controls both the laser emission device and the scanner. The laser machining apparatus scans the laser beam with the scanner to perform laser beam machining of a workpiece.
This type of laser machining apparatus can be used to perform laser beam machining on workpieces having three-dimensional shapes. However, when machining three-dimensional workpieces, it is often impossible to machine desired points on the workpiece due to the shape of the workpiece and the direction in which the laser beam is emitted from the scanner toward the workpiece. For example, when a non-targeted part of the workpiece is in the optical path of the laser beam being emitted toward a desired position on the workpiece, the non-targeted part of the workpiece will block the laser beam, preventing the beam from reaching the desired position on the workpiece.
One laser machining apparatus known in the art for machining three-dimensional workpieces is provided with a process condition setting unit for setting conditions for machining a desired pattern, unmachinable region detecting means for detecting unmachinable regions that will result in defective machining when attempting to machine in those regions according to the current machining conditions, and a display unit for displaying the unmachinable regions in a form different from the machinable regions. The unmachinable region detecting means detects both machinable regions and unmachinable regions on the workpiece when the workpiece is disposed in a prescribed position on the basis of the shape of the workpiece (see Japanese Patent Application Publication No. 2007-118051).
With this configuration, the conventional laser machining apparatus can make the user aware of the machinable regions and unmachinable regions on a workpiece prior to irradiating the laser beam. Accordingly, the user can rearrange the machining pattern onto a machinable region to avoid defective machining that would occur if the machining pattern were set in an unmachinable region.